Speed, Accuracy, and Flexibility Trade-Offs in on-Line Character Recognition

An on-line character recognizer was improved by making trade-offs on computation speed, recognition accuracy, and flexibility. Firstly, the error rate was halved by increasing computation precision at the expense of speed, achieving a character recognition accuracy of 97.3 percent. Secondly, without loss of accuracy, computation speed was increased by an order of magnitude over the original speed, to 85 characters/second on the IBM System 370/Model 3081. This was done by using a fast linear match to narrow the character choices for a slow but accurate elastic (non-linear) match. Some loss in flexibility resulted, however, because the linear match requires the same number of handwritten strokes for input and prototype characters. Also, the error rate of elastic matching was found to be about half that of linear matching.